Grab for excavating and elevating clay



No Model.) I 2 Sheets-Sheet 1.

G. J. HONEJ GRAB FOR EXOAVATING AND ELEVATING CLAY, GOAL, 61:0. No. 546,885. I Patented Sept. 24, 1895.

AN DREW B,GRAHAM. PHOTOUYNQWASHI NGrOrL D C (No Model.) 7 2 Sheets-Sheet 2.

' G. J. HONE. GRAB FOR EXGAVATING AND ELEVATING CLAY, GOAL, &c. No. 546,885. Patented Sept. 24, 1895.

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ANDREW B GRAHAM. vnoruumo WASHINGTDNDC llNrrn "t KO;

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GEORGE JAMES HONE, OF LONDON, ENGLAND.

SPECIFICATION forming part of Letters Patent No. 546,885, dated September 24, 1 895.

Application file November 21, 1894. Serial No. 529,502. (No model.)

-To all whom, it may concern:

Be it known that I, GEORGE JAMES Home,

- mast-maker, a subject of the Queen of Great Britain and Ireland, residing at East Ham, London, in the county of Essex, England, have invented certain Improvements in Grabs for Excavating and Elevating Clay, Coal, Coke, or other Material, of which the following is a specification.

This invention relates to improvements in the construction of excavators or grabs which are provided with an arrangement of sheaves mounted in sliding and fixed parts of the excavator-frame whereby a more powerful purchase is obtained on the material to be excavated, and the apparatus operates more efficiently than hitherto, and my invention further relates to details in the construction of such grabs or excavators.

According to this invention, one set of sheaves is mounted in a cross-head sliding in guides, the block for the second set of sheaves being secured to the base of the said guides.

In order that the invention may be clearly understood I will describe it with reference to the accompanying drawings, which illustrate a convenient way ofcarrying out this invention, in which Figure 1 shows the apparatus in side elevation with the blades or buckets open. Fig. 2 shows the apparatus closed, and Figs. 3 and 4 are plan views of the sheave-blocks, Fig. 3 showing the sheave-block on the sliding crosshead and Fig. a the sheave-block fixed at the lower part of the apparatus. Fig. 5 shows in section drawn to a larger scale aspring-buffer to which the end of the hauling-chain is attached for deadening the shock given by a sudden pull or jerk on the hauling-chain to that part of the apparatus to which the springbuffer is attached.

A represents blades or buckets pivoted at a to the lower end of a guide-frame O.

D represents tie-rods hinged at their lower ends (1 to the outer ends 0f the blades or buckets A and at their upper ends to the crosshead E, sliding in the guide-frame O, which cross-head is provided with sheaves e 6 To the lower end of the guide-frame O is secured I a pulley or purchase block F, containing sheaves ff f the relative position of the sheaves in the cross-head E and in the block F being shown in plan views, Figs. 3 and 4.

G is balanced chain attached to the crosshead at g for retaining the said cross-head in position.

H is the main hauling-chain passing from the crane through the central hole 6 in the cross-head E down through the hole f in the block F and round the central sheave fon the said block F. The chain then passes up over the sheave e on the cross-head E, returning down round the sheave f on the block F and up again round the sheave e on the crosshead E, then down round the sheavef on the block F, and, finally, up to the cross-head E, to the lower side of which it is attached throughaspring-bufterK,Fig.5. Thespringbutter K is formed by elastic blocks with interposing washers le up through which passes the connecting-link k havinga screwnut on the end of the link bearing on topmost washer, all being inclosed in a cylindrical case 70 with a metal cap 76 I have described this buffer as suitable for the apparatus, but other known forms of spring -buffers may equally well be used.

When it is desired to close the blades or buckets A for the purpose of excavating and removing the material, the said buckets being in an open position (shown in Fig. 1) and resting on the said material, the main chain H is hauled in, depressing the cross-head E and causing the tie-rods D to be thrust down, so that the blades or buckets A excavate the material and meet together in a closed position beneath the said material, as in Fig. 2. The apparatus may then be raised by continued hauling of the main chain H, and may be swung round to the desired position for discharging the load, which is effected in the ordinary manner by keeping the balance-chain taut and allowing the main chain to run out. The apparatus will then reassume the position shown in Fig. 1, and is ready for lowering again onto the material to obtain a fresh load.

By the arrangement of sheaves and pulley= blocks on the sliding and fixed parts, as here inbefore described, an increase of purchase is gained, which may be varied by using a greater or less number of sheaves in the pulleyblock and cross-head, according to the consistency of the material to be operated on and the greater or less purchase required to be exerted on the material to be removed.

I claim as my invention 1. In excavators or grabs, the combination of a guide frame provided with a block F carrying sheavesfififi and having a central holef, with a cross-head E sliding in the guide frame and provided with sheaves e, and c and having a hole a, rods connecting the blades with the cross-head, and a hauling 

